1. Field of the Invention
This invention relates to a drive motor for rotating disks, rotation in a disk drive.
2. Description of the Prior Art
In prior art disk drives used for recording and storing data, one or more disks are generally mounted to a rotary spindle that is coupled to and rotated by a drive motor. The drive motor is directly mounted to the spindle or coupled through a pulley belt to the spindle. The prior art disk drives required motor structures that were relatively large, were expensive to manufacture and maintain, and used a significant amount of power during operation.
As the disk drive technology progressed, the size of the disk has been made smaller presently employing 5.25" and 3.50" diameter size disks, as compared to the previous 14" and 8" diameter disks, and disk drives have become more compact yet capable of processing more highly packed data. However the motor structures were still relatively bulky, expensive and did not afford optimum efficiency. Such motor structures also did not lend themselves easily to automation techniques. In addition, prior known disk drives generally required a sensing device, such as a Hall sensor, associated with the rotary spindle to provide the angular position of the rotating disk. In this way, it was possible to determine which sector of the disk tracks was being addressed for recording or readout.